How do we get our credits for buying marvel omega stuff?

The credits should automatically be added to your account by the end of this month.

It should have been a credit back to the account that was used to buy the game.

Here's the article on that - https://support.xbox.com/en-US/games/purchasing/marvel-heroes-omega-refunds-and-credits

Marvel Heroes Omega was removed from the Microsoft Store on November 29, 2017, and the game is no longer available to play. If you purchased downloadable content (DLC) for the game then you will receive an automatic credit or refund to your account as follows:

• You will receive an automatic credit or refund if you purchased Marvel Heroes Omega DLC from the Microsoft Store between September 1 – November 29, 2017.
  
• For Marvel Heroes Omega DLC purchased between October 31 - November 29, 2017, your refund will be credited to your original payment instrument.
  
• For Marvel Heroes Omega DLC purchased between September 1 - October 30, 2017, your refund will be in the form of store credit.
  

Your refund or credit will appear in your account by January 31, 2018. The credit you receive will be in the currency matching your Microsoft account.

The issue was a little tricky at the time since the system was supposed to do an auto refund and Xbox Support was not able to process a refund.

Check your account to locate the initial purchase here -
https://account.microsoft.com/billing/orders

You can see the purchase/refund history of your account there.

If you see the purchase but no refund, you can contact Xbox Support for assistance. I believe the agent will need to get supervisor approval for a refund since it was supposed to be done already.

They may even be aware of an issue with refunds not processing as well.

Check your account for the purchase/refund and then contact support after that.

Also posted this in the xbox.uservoice,com forums (credit to Goggs25 on the insight).

https://xbox.uservoice.com/forums/363186--new-ideas/suggestions/32313745-marvel-heroes-omega-beyonde...

If you can go there as well and help this topic gain some traction, hopefully something will happen here.

Anyone who made a purchase on Marvel Heroes Omega between Oct 31st-Nov 29th 2017 will get a refund to their original payment instrument,ie credit/debit card etc.

Anyone who made a purchase between Sept 1st-Oct 30th 2017 will receive store credit.

Anyone who's played this game should have received a message from xbox live telling them this or should be getting this message soon or you can look here

Only some people will be refunded based on when they purchased the DLC. When did you buy it, was it before September 1st? IF so you wont be eligible. https://support.xbox.com/en-US/games/purchasing/marvel-heroes-omega-refunds-and-credits